有哪位过客知道北京哪个单位有压电力显微镜,我想做测试,可是苦于找不到哪里有这个设备!

压电力显微镜的压电响应模式成像：
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压电响应模式主要用来探测铁电材料的畴结构，其所用探针与静电力、磁力显微镜探针相同。它的成像方法是基于被探测的铁电体材料在外加一个直流电压后所引起的局部的压电振动，电压施加于探针与样品底电极之间，探针实际上起到一个可动上电极的作用。压电信号相位取决于极化方向，极化取向相反的区域在电场作用下彼此反向振动，在压电响应图像上表现为不同衬度的区域。

 

拷贝的资料:

The basic idea of Piezoresponse Force Microscopy (PFM) is to effect locally the piezoelectric sample surface by the electric field and to analyse resulting displacements of the sample surface[1].
The PFM technique is based on the converse piezoelectric effect, which is a linear coupling between the electrical and mechanical properties of a material. Since all ferroelectrics exhibit piezoelectricity, an electric field applied to a ferroelectric sample results in changes of its dimensions.
To detect the polarization orientation the AFM tip is used as a top electrode, which is moved over the sample surface. In the Intro1 animation one can see the reaction of out-of-plane and in-plane domains in the ferroelectric film on the voltage applied to the scanning tip in Contact Constant Force Mode. The electric field generated in the sample causes the domains with the polarization parallel to the field to extend and the domains with opposite polarization to contract.
If the polarization vector is perpendicular to the electric field, there is no piezoelectric deformation along the field direction, but a shear strain appears in the ferroelectric, leading to displacements of the sample surface parallel to itself, along the polarization direction.
The AFM probe tip moving according to the surface displacement causes cantilever normal or torsion (because of friction) deflections. Direction of the deflection depends on the mutual orientations of the electric field and domain polarization. Correspondingly in the case of the AC electric field phase lag between the electric field and cantilever deflections will depend on the their mutual orientations. In general case by analyzing the amplitudes and phases of the normal and torsion cantilever vibrations one can reconstruct the sample domain structure.

 

 

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